Cows stand patiently in a tent-like chamber at a research farm in western Wisconsin, waiting for their breath to be tested. Outside, corrals have been set up with equipment to measure gas wafting from the ground. A nearby corn field contains tools that allow researchers to assess the effects of manure spread as fertiliser.
Scientists based at the University of Wisconsin-Madison have started a slew of studies to determine how dairy farms can reduce their greenhouse gas emissions. They will look at what animals eat, how their waste is handled and the effects on soil, water and air.
Their work is part of a government-sponsored effort to help farmers adapt to more extreme weather and reduce their impact on climate change. The studies also will support a dairy industry effort to make farms more environmentally friendly, profitable and attractive to consumers. The Innovation Center for US Dairy is developing a computer program that will allow farmers to compare water consumption, energy use and greenhouse gas emissions from their farms to the national average and learn how improving their practices could help their bottom line.
"We like to say sustainability makes cents - c-e-n-t-s," said Erin Fitzgerald, the centre's senior vice president for sustainability.
Environmentally speaking, the big issue for dairy farms for decades has been manure.
Karl Klessig remembers state agents coming to his farm in 2002 and handcuffing him after an unexpected rain washed manure spread several days earlier into nearby Lake Michigan. Klessig was told that if his family didn't immediately till the manure into the ground, tearing up the grass that feeds their cows, he'd be jailed.
It was a big loss, but it "jump-started" their environmental awareness, Klessig said. The family welcomed researchers from UW-Madison and UW-Extension onto its property in Cleveland, about 112km north of Milwaukee, for tests that had some unexpected results.
For example, the family had been leaving its pastures untilled for up to a decade to allow the grass to build up density, feeding the cows and reducing erosion. But scientists found that also allowed phosphorus to accumulate in the top layer of soil. Klessig said his family had been able to reduce phosphorus by tilling pastures more often and growing corn, which uses phosphorus to grow.
They also learned the farm was losing hundreds of pounds of soil each year through its drainage system and wormholes were allowing manure to run into those pipes. It was nerve-racking to have researchers point out these problems, Klessig said.
But the scientists also offered solutions, which Klessig said.
Such studies have helped provide the basis for the computer program being developed by the Innovation Center. The tool will be bolstered by data from a $US10 million ($A11.22 million) project led by UW-Madison but including scientists, engineers and scholars from many universities.
It is one of four projects funded by the US Department of Agriculture to help farmers in specific regions adapt to climate change while reducing their environmental impact, said Ray Knighton, national program leader for soil and air quality at USDA's National Institute of Food and Agriculture. The other projects involve the beef, wheat and wood production industries.